1. Field of the Invention
The invention relates generally to devices and methods for operation and monitoring operational details of downhole seal assemblies. In particular aspects, the invention relates to arrangements for such monitoring of seal assemblies that incorporate metal bellows style chambers.
2. Description of the Related Art
Electric submersible pump (ESP) assemblies are routinely used in the production of hydrocarbons from wells. A typical ESP includes a downhole motor that generates power used to operate a pump device. A seal assembly or seal section is typically provided between the motor and pump. The seal assembly includes an outer housing and shaft that is used to transmit torque from the motor to the pump. The seal equalizes fluid pressure so that the inside of the motor and seal are at equal pressure with the wellbore or outside environment. The seal assembly usually provides a series of chambers that prevent or slow ingress of well fluids from the seal head to the motor. The seal also allows for motor oil thermal expansion and contraction.
The chambers of the seal assembly can have various configurations. Labyrinth-style chambers and barrier-style chambers are two known types. Two types of barriers are elastomeric and metal bellows.